Quartavious Davis was convicted of various robberies during which he possessed a gun. He was sentenced to 162 years. His primary argument on appeal was the the Government obtained his cell phone's location information from his wireless provider by court order under the Stored Communications Act rather than by search warrant. Unlike a search warrant, the SCA does not require a showing of probable cause. The Government used the location data Davis at trial to show that as to six of the seven robberies, Davis and his co-defendants placed and received cell phone calls around the time of the robberies near the locations of the stores that were robbed. The 11th Circuit ruled Davis had a valid privacy interest in his location under the Fourth Amendment, and obtaining the data via an order under the SCA (section 2703(d)) was unconstitutional. The opinion is here.

In the first ruling of its kind nationally, a three-judge panel of the 11th U.S. Circuit Court of Appeals determined people have an expectation of privacy in their movements and that the cell tower data was part of that. As such, obtaining the records without a search warrant is a violation of the Fourth Amendment's ban on unreasonable searches and seizures, the judges ruled.

However, Davis gets no relief from the Court because of the violation. The Court determined the "good faith" exception to the exclusionary rule applies under United States v. Leon. [More...]

The Supreme Court ruled warrantless GPS monitoring of Antoin Jones violated his Fourth Amendment rights and could not be used at his trial. (Opinion here, background here.) Basically,

The case concerned Antoine Jones, who was the owner of a Washington nightclub when the police came to suspect him of being part of a cocaine-selling operation. They placed a tracking device on his Jeep Grand Cherokee without a valid warrant, tracked his travels for a month and used the evidence they gathered to convict him of conspiring to sell cocaine. He was sentenced to life in prison.

The Government then sought to introduce cell site locator data obtained by a court order (but not a search warrant establishing probable cause.) The judge has now ruled the cell site data can come in at trial. She said she didn't have to rule on the issue of whether a search warrant is required because the good faith exception to the warrant requirement saves the search. Wired's report is here.